Arteriosclerosis proceeds over a long period of time without subjective symptoms, and induces cardiac diseases such as severe myocardial infarction or cerebrovascular diseases such as cerebral infarction or cerebral hemorrhage. Arteriosclerosis progresses to result in the formation of atherosclerotic lesions (atheroma or plaque) within arterial blood vessels. Plaques include stable plaques rich in calcified fibrous tissue and unstable plaques rich in lipids or inflammatory cells, in which fibrous caps are thinned. Most acute atherosclerotic diseases such as myocardial infarction and brain infarction are induced by rupture of unstable plaques and thrombus formation. Therefore, it is important to appropriately evaluate and diagnose the formation and growth conditions of unstable plaques and the rupture risk thereof in acute atherosclerotic diseases. Arteriosclerosis is currently detected mainly by angiography, which involves evaluation of the degree of stenosis, but it is problematic because information concerning intravascular plaque formation or the properties thereof can barely be obtained. Moreover, angiography is highly invasive. Hence, a low-invasive method for detecting atherosclerotic lesions has been required.
Disease proteomics is a technique for exhaustively searching increases or decreases in protein levels that vary depending on specific diseases when compared with a healthy state, using a body fluid such as blood, saliva, or urine, or a tissue sample, as a material. Disease proteomics is a technique characterized by enabling simultaneous extraction and/or detection of a plurality of factors, the association of which with diseases is conventionally unknown. Application of multiple specimens to and increased sensitivity for a 2D electrophoresis method and measuring apparatuses such as protein microarrays and mass spectrometry have been realized. Thus, data analysis technology has been in place and is applied in searches for markers for various diseases including cancer, immunity disorders, infections, and the like (Non-patent document 1).
For example, methods for diagnosing arteriosclerosis or diseases associated therewith by using biochemical markers have been reported, wherein the blood levels of the biochemical markers vary as atherosclerotic lesions develop, (patent documents 1 and 2). However, further development of marker groups is desired in order to precisely diagnose atherosclerotic lesions.